Riot control charges



United States Patent 3,391,036 RIOT CONTROL CHARGES Peter James RobertBryant, Salisbury, Albert Richard Owen, Bridgwater, Somerset, and FrankSidney Scanes,

Salisbury, England, assignors to the Secretary of State for Defence inHer Britannic Majestys Government of the United Kingdom of Great Britainand Northern Ireland, London, England No Drawing. Filed Dec. 23, 1966,Ser. No. 604,492

6 Claims. (Cl. 14919) The invention relates to methods for subduing orcontrolling agitated or aggressive people, such as rioters orlawbreakers, by means of chemical agents hereinafter called riot-controlagents which are dispersed into the atmosphere.

British patent specification No. 967,660 describes riot controlapparatus comprising a container which houses a charge containing ariot-control agent which is o-fluoro-, o-chloro-, o-bromo-, o-nitro-,o-cyanoor o-hydroxymalononitrile and which has means for emitting thecharge so that it is dispersed in a particulate form into thesurrounding atmosphere. In a preferred form of apparatus described thecharge consists of an orth-o-substituted benzal malononitrileriot-control agent admixed in a self-combustible composition whichevolves gas on combustion in which the ortho-substituted benzalmalononitrile is entrained without complete decomposition, and suitableself-combustible compositions which may be admixed With the riot-controlagent to form the charge are described. Such charges are most oftencomposed of mixture of dry, powdered constituents which have to 'be usedin a consolidated state in order to control their rate of burning. Inpractice, the consolidation by pressing or pelleting the powdered chargecan only be carried out satisfactorily in a cylindrical mould and astrict limitation is consequently placed upon the design of the chargecontainer. This design limitation often prevents containers intended foruse as projectiles from being formed in the most advantageous shape; forexample, a cylindrical hand grenade can be thrown only by a lobbingaction, which restricts its range considerably. Furthermore, thepackaging and storage of cylindrical containers is inefficient.

It is an object of the present invention to provide an ignitable orself-combustible riot-control charge containing one of saidortho-substituted benzal malononitrile riot-control agents which chargedoes not require conventional consolidation within a charge container,and which may be filled into a charge container of any desired shape.The present invention also aims at providing such charges which havesufiicient cohesive strength and inertness to be capable of use withoutrequiring to be housed in a container.

According to the invention, an ignitable or self-combustibleriot-control charge comprises o-fluoro-, o-chloro-, o-nitro-, o-cyanooro-hydroxy-benzal (alternatively named benzylidene) malononitrile admixedwith a polyester resin to yield a charge which may be formed into anydesired shape and subsequently hardened to a solid, cohesive mass.

The ignitable charge in addition preferably contains an oxidising agentand a combustible organic fuel for example, lactose, sucrose or wheatstarch. A small quantity of a stabilizer may be included, for example ametal oxide or carbonate, and also an inert absorbent material such askaolin may be added in minor proportion to avoid local drowning of thecharge owing to melting of one of the constituents.

The oxidising agent is preferably an inorganic oxidising agent such as anitrate, chlorate or perchlorate and the proportion of oxidising agentis chosen to give the ignitable charge a desired rate of burning. Alarge excess of oxidising agent over that proportion required for com-3,391,036 Patented July 2, 1968 ice plete combustion of the charge isundesirable as the charge would then be objectionably frictionsensitive.

The polyester resin is preferably one which will set i.e. cure, attemperatures below about 60 C. and most conveniently at room temperaturein a reasonably short period of time i.e. up to about four hours. Atypical polyester resin which may be used in the riot-control chargeprovided by the present invention consists of 30% styrene and 70% of apolyester consisting of linear condensation products of propylene glycolwith phthalic or maleic acid. However, a wide variety of commerciallyavailable polyester resins may be used includes A250, 262/32, and 2591(British Resin Products Ltd.); SR17438, 17449, 18979, 19095, 19229(Bakelite Ltd); Crystic 189, 195, 197 and Marco 5B.28D (Scott B-ader andCo.

The curing of the polyester resin may be initiated by a peroxidecatalyst such as methyl ethyl ketone peroxide. A suitablecommercially-available catalyst is Cello'bond X7764 (British ResinProducts). A promoter such as cobalt naphthenate may be usedadvantageously and a suitable commercially-available promoter isCellobond X7761 (British Resin Products).

The polyester resin may replace part or all of the proportion of fuelprovided in self-combustible charges described in British patentspecification No. 967,650 in addition to acting as a binder for theother charge ingredients.

When admixed with the said ortho-substituted benzal malononitrilederivatives and any desired additional ingredients, the polyester resinyields a charge which is initially in a plastic condition and whichconsequently may be readily filled into containers of any shape andtherein finally set to a solid charge. This solid charge has betterstorage characteristics than prior charges since the polyester resintends to encapsulate and thus protect the other ingredients of thecharge from the storage environment. Furthermore, the resistance of thenew charges to water is improved by the resinous coating, and thehazards,

from dust for example, of handling these charges are much reduced.

The ignitable charges provided by the present invention are solid whenset and have considerable cohesive strength owing to the presence of thepolyester resin and it is clearly within the scope of the presentinvention to provide unconfined free-burning blocks of resin-bondedcharges which are water-proof, require no special packaging and arestrong enough to be propelled 'by conventional methods.

A typical example of a process for preparing the ignitable chargesprovided by the invention will now be described.

The finely-divided solid components of the charge are sieved to removeobjectionable aggregates and weighed quantities are mixed by hand or ina drum mixer and the mixture is sieved once more. An excess of thepolyester resin is then weighed out and a catalyst and any promoterrequired is added at this stage. The correct amount of catalysed resinis then poured into a mechanical mixer (for example, a Beken DuplexMixer) and the mixed solid components are added. Mixing is carried outfor at least 15 minutes to yield a plastic composition which may befilled into a container of any desired shape by any suit-able method(e.'g. hand-stemming, pouring or extrusion chosen to suit the viscosityof the plastic composition).

A typical composition range by weight for ignitable charges inaccordance with the invention is as follows:

Percent o-Substituted benzal malononitrile 25-40 Polyester resin 15-30Oxidizing agent 20-35 Oxidizable fuel 0-15 Other conventional additives.including inert ipsor ents such as kaolin, may be included in the:narges.

Particular examples of ignitable charges will now ae described.Proportions are given as percentages b weight.

Example 1 tirrcen o-Chloro benzal malononitrile -1 Polyester resin(British Resin Products $162.32; .5 Potassium chlorate oxidizing agent qLactose fuel Kaolin This charge has a burning rate or 0.15 cmm sec. anddisperses into the atmosphere unchanged up to about 90% of itso-chloro-benzal malononltrtle content.

Example 2 tutcent o-Chloro benzal malononitrile u Polyester resinBritish Resin Product's A262/32l ,8! Potassium chlorate oxidising agent-J This charge is a slower burning charge than that or Example 1 (havinga burning rate of 0.015 a cmfi sec.) in which conventional fuel has beenreplaced completely by polyester resin.

Example llllt'tlfinl o-Chloro-benzal malononitrile N Polyester resin(British Resin Product's A262/32) .0 Potassium chlorate oxidising agent,J Lactose fuel The burning rate of this composition is 0.67 1,.cm.-=sec.

Example 4 ttrcen o-Chloro-benzal malononitrile to Polyester resin{British Resin Products A262/32l .0

Potassium chlorate oxidising agent -1 Kaolin The burning rate of thiscomposition iS 0.015 cms sec.

liixample 5 o-Chloro-benzal malononitrile Polyester resin (British ResinProduct's A262/32 Potassium chlorate oxidising agent -1 Lactose fuel Theburning rate of this composition 0.052 2.. emf sec.

Example 6 tlrcent o-Chloro-benzal malonomtrile .ti

Polyester resin {British Resin Products A262. 32) Potassium chlorateoxidising agent Lactose fuel mposition 1 Percent wopnen resin 37.5rdener 7.5 tutllin 10.0 i tassium :nlorate 45.0

.Iupcopnen Resorcmal Resin is manufactured by Leicester m Lovell andCompany Ltd.

lllglipmposltion 2 Percent ll'uacopnen resin 37.5 rtrdener 7.5tittassium :nlorate 55 t ed Phosphorus 50 ife claim:

w ll! tgnitable or self-combustible riot-control compotttpn whichcomprises, o-fiuoro-, o-chloro-, o-bromo-, 0- :u;ro-. ul-cyano-. pro-hydroxy-benzal malononitrile ad- .nlxed with a polester resin.

tn tgnitable r self-combustible riot-control comsition which comprisesby weight about -40% 0- .oro-. a-cnloro-. p-bromo-, o-nitro-, o-cyano-,or o-hyuxy-malononltrile, about 15-30% polyester and about oxidisingagent.

A composition as claimed in claim 2 and in which lltll oxidising agentis potassium chlorate.

ll. A composition as claimed in claim 2 and in which and polyester resinconsists by weight of about 30% i5 ttyrene and about of the linearcondensation prodtcts from propylene glycol and phtthalic or maleicacid.

A composition as claimed in claim 2 and which contlns up to l5% byweight of an oxidisable fuel.

A. composition as claimed in claim 5 in which said is lactose.

l llleferences Cited 11 WITED STATES PATENTS H.335 #3967 White et al.1674O lENJAMIN PADGETT, Primary Examiner.

2. AN IGNITABLE OR SELF-COMBUSTIBLE RIOT-CONTROL COMPOSITION WHICHCOMPRISES BY WEIGHT ABOUT 25-40% OFLUORO-, O-CHLORO-, O-BROMO-,O-NITRO-, O-CYANO-, OR O-HYDROXY-MALONONITRILE, ABOUT 15-30% POLYESTERAND ABOUT 20-35% OXIDISING AGENT.